Multi-stage turbomachines, such as, for example, thermal gas turbines, often include an annular guide vane assembly between each two adjacent rotor stages. At least part of these annular guide vane assemblies are equipped with variable guide vanes to selectively deflect the respective working fluid of the turbomachine such that the working fluid impinges on the downstream rotor stage at an optimum angle. The variable guide vanes are rotatably supported at their one ends in an outer ring or casing or the turbomachine and at the other ends in an inner ring.
DE 10 2005 042 747 describes a gas turbine including an annular guide vane assembly disposed as a stator stage in a compressor, the annular guide vane assembly having an inner ring composed of elastically deformable semicircular ring segments. To assemble the inner ring, the inner ring is deformed until radially inner trunnions of the guide vanes can be positioned in respective bushings of the inner ring. Upon relaxation of the inner ring, it is connected to a support.